File



Patented Oct. 25, 1932 UNITED: STATES ALFRED PEISELER, OF REMSCHEID-HADDENBACH, GERMANY FILE Application filed March 19, 1930, Serial No. 437,139, and in Germany March 23, 1929.

This invention relates to improvements in files, and more particularly to files which have their teeth subdivided by filings breaker grooves such as are'customarily in use with milled files.

Whilst files of the type referred to have their filings breaker grooves made of identical shape throughout, my improved file is provided with grooves differing in their shape from one another in such a manner that the width of said grooves changes over the Whole length of the file body. Owing to this novel feature, a particularly high productiveness will be obtained, especially when using the file in connection with shapers of high capacity, the said shapers being eventually provided with a liquid cooling device of any kind. The advantageous action of my improved file is chiefly obtained at those places of the file surface where the filings breaker grooves are made wide and their respective intermediate tooth points narrow, this construction causing the tool to exert a very sharp filing action, the pressure load employed being a relatively insignificant one whereas the following teeth having their respective filings breaker grooves made narrower, are smoothing the surface to be operated upon.

Another object of my invention consists in varying the width of the said filings breaker grooves in such a manner that, 1n certain places of the file body, the latter may carry grooves of extremely small cross-section, or no grooves at all, and that in other places of the file body, the width of said filings breaker grooves is increasing to such an extent that these grooves are finally larger in width than the intermediate tooth points.

The accompanying drawing shows one embodiment of the invention by way of example, the improved device being indicated diagrammatically.

Fig. 1 is a top plan view of my improved file; I

Fig. 2 is an enlarged top plan view of a series of subdivisions of the file body, the said subdivisions following one another in longitudinal. direction; and

Fig. 3 showstransverse sectional views of the subdivisions with respect to Figure 2.

Referring to the drawing, the reference character adesignates the file body proper provided with milled teeth I), b, which, as shown in the subdivision indicated by I, extendundivided over the whole breadth of the file body, as shown in the next subdivision indicated by II, the file teeth 6 are subdivided by filings breaker grooves c of relatively small cross-section. The said grooves increase in width towards the other end of the file body in such a manner that they will finally be half as wide as the intermediate tooth edges, as shown in the subdivision indicated by III; in the next subdivision indicated by TV, is shown that the said filings breaker grooves are larger in cross-section than their respective tooth edges. Simultaneously with the increasing width of the said grooves, there may take place an increase in the direction of depth, as shown in the subdivisions of Figure 2., The filings breaker grooves having reached their utmost width, they may then be reduced in width progressively, as shown in the subdivision indicated by V, and the arrangement described maybe repeated as many times as desired.

The filings breaker grooves may be obtained bymeans of a cutting machine, the P latter beginning with cutting at the holder end of the file body; the points of the teeth may at the same time be pressed somewhat forward, this arrangement facilitating th filing action of the tool. I i

It is not desired to confine this invention to the specific construction, combination, and arrangement of parts herein shown and described, and the right is reserved to make all such changes in and modifications of the same as come within'the spirit and scope of the invention.

What I claim as new, is

1. A file ofthe character described, the body proper of which is provided with milled teeth at one end, which teeth extend undivided over the whole width of the file, the remaining teeth being subdivided by filings breaker grooves of gradually increasing 7.

width, there being a gradual increase in the direction of depth, with the next succeeding grooves reduced in width progressively.

2. A file having parallel cutting teeth extending from edge to edge of the file, said teeth forming a plurality of sets arranged in succession longitudinally of the file, each set having a series of its teeth intersected by breaker grooves cut through the teeth to form notches in the cutting edges of the cutting teeth, the breaker grooves being widest at the central portion of each set and tapering in width toward each end of the respective set.

3. A file having parallel cutting teeth extending from edge to edge of the file, said teeth forming a plurality of sets arranged in succession longitudinally of the file, each set having a series of its teeth intersected by breaker grooves cut through the teeth to form notches in the cutting edges of the cutting teeth, the breaker grooves being widest at the central portion of each set and tapering in width toward each end of the respective set, said breaker grooves further being deepest at the central portion of each set and tapering in depth from the said central portion towards each end of the respective set.

4. A file having parallel cutting teeth extending from edge to edge of the file, said teeth forming a plurality of sets arranged in succession longitudinally of the file, each set having a series of its teeth intersected by breaker grooves cut through the teeth to form notches in the cutting edges of the cutting teeth, the breaker grooves being widest at the central portion of each set and tapering in width toward each end of the respective set, the cutting teeth at the ends of the sets extending uninterruptedly frdln one edge of the file to the other.

5. A file having parallel cutting teeth ex tending from edge to edge of the file, said teeth forming a plurality of sets arranged in succession longitudinally of the file, each set having a series of its teeth intersected by breaker grooves cut through the teeth to rorm notches in the cutting edges of the cutting teeth, the breaker grooves being widest at the central portion of each set and tapering in width toward each end of the respective set, said breaker groovesfurther being deepest at the central portion of each set and tapering in depth from the said central portion towards each end of the respective set, the cutting teeth at the ends of the sets extending uninterrrupted from one edge of the file to the other.

In testimony whereof I have affixed my signature.

ALFRED PEISELER. 

